Let's assume Bob has something Sue wants, but Bob has nothing to offer Sue.  Sue asks Bob for a promise, instead of a utility.  This is represented by Bob giving Sue some money.  Sue can now take this money, and use it to redeem a promise from someone else, let's say Joe, who has something of value to her.  Joe in turn does the same thing to someone else, and this repeats until such time as that someone else wants something from Bob and redeems a promise of equal value.

The total amount of money in circulation at any given time represents the sum of all promises made by society to pay them back.  Why is it, then, that for any given transaction, the amount of 'promises' redeemable by a provider need to be the same as the amount of 'promises' given by the purchaser?  If you think about what the registry does when it 'prints money' to give to the purchaser - it's essentially stating who ever purchased the utility does not have to work as much as the provider to get it.  Which is like saying the provider worked harder than the purchaser.  Which is like saying the provider 'gave' something to the purchaser more than what was owed.  But, he didn't, because the provider still got paid, and can use that money to get more out of society than he would have otherwise.  So it's 'society' that is giving the 'units of account' to the provider.  For those of you who read about this sort of thing - you can think of this as an implementation of a 'gift based economy', or 'ubuntu', except the gift is not completely free or 'poisonous',

What happens when someone hords these promises?  This is like doing something for someone, and after a really long time later, you say to someone "Rembemer when I did ... for this other person a really long time ago?  I want ... from you in return now".

What is that someone going to think about that thing they did for someone a long time ago?  The Registry considers this behaviour unfair and represents this by the lack of ability to accumulate a high amount of wealth for an individual through the implementation of Transients.

What it also does is what an economy is supposed to do - manage scarce resources. Utilities which are not scarce are cheaper for the provider, but the vendor receives the same amount otherwise.

There is also a basic income which is redeemed by the exchange of everyone's free time that is not allocated towards utilities.

The most finite resource is everyone's time.  Whenever you are competiting with another individual over a scarce resource, you can use promises you have redeemed as a tool to win the competition, as opposed to something worse like physical force or other forms of persuation.